How do I hide a button in a repeater's item when its dB field is empty?

[contact13073]

Got this far, but still, the button collapses in all items:

$w.onReady(() => {
  $w('#repeater1').onItemReady(($item, itemData, index) => {
	let url = itemData.url;
 	if (url === "" || url === null || url === undefined) {
 		$item('#button8').collapse();
	}
  })
});

What am I doing wrong?